Romney going first, given a chance to attack Newt — a good theory, except I can’t envision Romney starting out that way. He’s really not good at frontal attack and initiating same. They’ll need a very leading question.
Bachmann on the other hand would kneecap Newt without an invitation. So would Ron Paul!
Bachmann attacks other candidates as an end in itself. It never benefits her, but she just keeps doing it anyway. She likes it.